Notes
PhD thesis is divided in a complex of research cases in the field of oxygen optical sensor, based on 4,7 - diphenyl - 1, 10 - phenanthroline ruthenium(II)dichloride complex - (Ru(dpp)3). The purpose of PhD thesis is to improve optical features and response of a sensor based on Ru(dpp)3. Additional research of sensor features was carried out with an emphasis on various techniques of making sensors, modification of dye concentration, application of different polymeric supports, influence of the interference effect and an emphasis on implementation of nanoparticles. Afterwards, oxygen optical sensor was made, using different techniques of sensor solutions applications (Žspin coatingŽ technique, using device for a thin layer and mechanical application). The purpose of the abovementioned was to prepare the most homogeneous sensor solution in order to obtain the most optimal sensor features. Applying sensor solutions with mechanical application is simple andthe most cost advantageous technique. However, this technique has not proven to be the most appropriate, because it is difficult to ensure a homogeneous coating over the entire sensor surface. We found out that the mainadvantage of spin-coating use is its velocity, simplicity and its suitability for application of smaller volumes. It also enables a production of various series of sensors with different features and minimal reagent use. The spin coating method has proved effective when applying sensor solutions inlaboratories, but it does face a few difficulties when it comes to preparation of homogeneous coating (150 ŽL of sensor solution, 80 mg of Ru(dpp)3, chloroform, silicon E41, Dataline foil, spin coater programme set on: 1st step: 750 spins Ž 3 s, 2nd step: 300 spins Ž 3 s and 3rd step: 150 spins Ž 3 s). The most suitable method of applying sensor solutions is device for thin layer where the thickness of sensor solutions amounts to 10 Žm, 15 Žm, 20 Žm, 25 Žm, 30 Žm, 40 Žm and 50 Žm. Such manufacturing method enables the most homogeneous application of sensor solution; it is fast, simple and enables a composition of sensors with reproducible properties. By adding various metal nanoparticles and Triton - X - 100, characteristics of the sensors were improved. When using the sensors in existing conditions, the content of oxygen during biodegradation was observed. Electrochemical sensors have limits, (electrodes, consisting of noble metals which react with corrosive gases); therefore they are not suitable for such application. Afterwards, the concentration of oxygen in decomposition of organic waste was observed with an oxygen optical sensor based on Ru(dpp)3. Furthermore, decomposition of mixed organic waste with microorganisms in automatic compost bin was studied, which is the most effective method when making the compost athome. For optimal working of an automatic compost bin, further studies are needed, which will include different conditions, (various strata and blends ofstrata, a selection of microorganisms, monitoring the occurrence of gas, etc.). Applicability of the sensor we developed was tested in the field ofbiogas and its measurements. Measurements which can be carried out on-line or in-situ can tell us a little more about the process itself and as such givea chance to optimize the process of biogas production. The measurement of oxygen concentration in pilot bioreactor has proven that oxygen optical sensoris suitable for measurement of oxygen in biogas. The advantages of the sensor are the following: it is easy to use, enables measurements in water or in gas phase, is explosion proof and the measurements can be carried out in wells where negative and positive pressure is present.